Randomized comparison of cavotricuspid isthmus ablation for atrial flutter using an open irrigation-tip versus a large-tip radiofrequency ablation catheter.

BACKGROUND Large-tip (10 mm) catheters (LTCs) and open-irrigation-tip catheters (OITCs), both capable of creating large lesions, are more effective than conventional catheters for cavotricuspid isthmus (CTI) ablation. However, it is not clear whether complete CTI block can be achieved more efficiently using an LTC or an OITC. The purpose of this study was to compare the efficiency of radiofrequency catheter ablation (RFA) of the CTI using LTC versus OITC to eliminate atrial flutter (AFL). METHODS AND RESULTS Sixty consecutive patients (age = 62 ± 10 years) with typical AFL were randomized to undergo RFA of CTI using an LTC (10 mm) or an OITC. If complete CTI block was not achieved by ≤30 minutes of RFA, patients were allowed to cross over to ablation with the other catheter. A 3-dimensional electroanatomical mapping system was used for catheter navigation only with the OITC. The mean duration of RFA to achieve CTI block in 50% of the patients was 6.8 ± 2.2 minutes with an LTC and 11.7 ± 2.7 minutes with an OITC (P = 0.001). After 30 minutes of RFA, CTI block was achieved in 26/30 (87%) and 25/30 patients (83%) using an LTC and an OITC, respectively (P = 1.0). After crossover, CTI block was achieved in 4/5 (80%) and in 4/4 patients (100%) with an LTC and OITC, respectively (P = 1.0). LTC was associated with a lower volume of intravenous fluid administration (388 ± 365 mL versus 865 ± 451 mL, P = 0.0001) and a trend for shorter procedure duration (95 ± 31 minutes versus 114 ± 50 minutes, P = 0.09) than the OITC. At 6 ± 3 months, 30/30 patients (100%) in the LTC and 27/30 patients (90%) in the OITC groups remained free from AFL, respectively (P = 0.24). Except for one inconsequential steam-pop during RFA with the OITC, there were no complications. CONCLUSIONS Complete CTI block is achieved more rapidly using an LTC than an OITC, and with a similar clinical efficacy.